Grinding machine



y 9, 1956 K. HEESEMANN 2,747,341

GRINDING MACHINE Filed April 21, 1953 FIG-7 v INVAWMP KARL HEEJEMANN A TTORNEYS GRINDING MACHINE Karl Heesernann, Bad Oeynhausen-Rehme, Germany Application April 21, 1953, Serial No. 350,118

Claims priority application Germany April 28, 1952 Claims. (Cl. 5I-141) This invention relates to grinding machines, and more particularly to a profile and edge grinding machine.

Hitherto the grinding of profiled workpieces, especially in the wood-working industry, has been done by hand. All attempts to have this operation performed mechanically have been in vain, although it has been endeavored to grind simple profiled workpieces consisting only of concave and convex planes, on the standard sand belt. In this operation the inner surface of the belt, however, being pressed by hand against the profile of the workpiece by means of a suitable piece of material, the grinding process is not entirely mechanical, and for this reason requires considerable time and energy. Complicatedly-shaped wooden workpieces cannot be ground at all in this way.

The grinding of edges, particularly when they are veneered, is also still done by hand or by way of expedient on the standard sand grinder.

It is the object of the present invention to provide a machine for mechanically grinding all kinds of profiled workpieces and veneered edges which comprises a column, two laterally extending arms integral with said column, two rotary flanges, every one of which being mounted to the free end of each of said arms, a motor mounted to one of said rotary flanges and carrying a roller driven by said motor, a second roller mounted to the other rotary flange, an endless sanding belt led around the two rollers, an adjustable guiding means shaped conforming to the workpieces to be ground and interchanegably disposed between said two rollers in the same plane so as to form a triangular unit, a tightening equipment mounted to said other rotary flange and adapted to adjust the sanding belt by means of said second roller, and an adjustable table disposed in front of said column and adapted to carry the workpieces, said sanding belt being of such width that its edges project beyond the guiding means and are guided by suitable equipment.

The invention is illustrated in the accompanying drawings by way of example, but it is understood that the invention is not restricted to the embodiments herein shown. In the drawings,

Fig. 1 is a front elevational view of a profile and edge grinding machine;

Fig. 2 is a top plan view thereof;

Fig. 3 is an enlarged elevational view of a profiled roller and guide rollers for guiding the sanding belt;

Fig. 4 is a top plan view thereof;

Fig. 5 is a side elevational view of a contact roller for grinding veneered edges; and

Fig. 6 is a top plan view thereof.

Referring now to the drawings, in which the same numerals refer to like elements, the profile and edge grinding machine in accordance with the invention comprises essentially a column a, rollers b and c, a profile roller :2, a sanding belt e, a table f, and a driving motor g.

One end of the column a is provided with the motor g mounted on a rotary flange a and the other end is provided with a device for tightening sanding belt e which is mounted on another rotary flange a In Figs. 1 and 2 States Patent 0 the broken line a denotes the longitudinal axis of the column and on which axis the flanges 8 and 8 center.

Roller b is mounted on the free end of a vertical motor shaft g while roller 0 is disposed on the free end of a shaft i carried by the device for tightening sanding belt e. Said device consists of a support i, movable by means of a spindle h, whereby the support i is prevented from tipping by guide bars 1'.

To spindle h is attached a handwheel h which by means of a compression spring k presses against a base I designed to connect the two guide bars j. By this arrangement the belt tension is given the necessary elasticity.

By turning the handwheel I1 either to the right or left the distance between rollers b and 0 can be varied to such a degree that the sanding belt e has always the correct tension.

Atop column a a guide member 111 is disposed wherein a shaft 11 has a to-and-fro motion as indicated by the arrow shown in Fig. 2.

A guide means 0 is so disposed on the shaft n that it is height-adjustable. A holder 2 for profile roller d or a contact d is so connected to guide means 0 that, by means of an axle q, the holder p is adjustable.

The surfaces of profile roller 01 and contact roller d are preferably made of felt or a material of similar qualities. Holding arms r are also connected to guide means 0, upon which are mounted holders r and r which individually are adjustable about the center of the holding arms r. In holders r and r shiftable bearings s and s are height-adjustably disposed, while holding arms s are slidably journalled in the shiftable bearings s and s in the direction of arrow.

In Fig. 3, holding arms s are provided with guide rollers t and t for guiding sanding belt e which in some width along its edges has been made inoperative either by having a twilled cloth or any other suitable material glued over or by having the abrasive means removed in order not to have the guide rollers t and t damaged by the abrasive.

The table 1 is pivotally disposed about an axle f by means of height-adjustable guides f enabling said table to be angularly adjustable to both sides. The guides f are height-adjustable along guide pieces f making it possible for said table to be adjusted in height. The guide pieces 1? are connected with shafts u mounted on column a in such a way as to render the table adjustable in the direction of arrow as shown in Fig. 2. Stop bars are replaceably mounted on table 1.

An important feature of the present invention is the fact that the edges of the sanding belt e project beyond the profile roller d and are specially guided, e. g., by means of'rollers or ways t, t Preferable is the use of rollers because of friction being to a very high degree eliminated.

In order to avoid grinding of the workpieces within the range of the sanding belt edges the abrasive such as emery need not, as mentioned above, be applied at the places under consideration. Sanding belt edges, however, to which has been applied the abrasive, may beprovided with a glued-on strip of cloth v or such material, or with a gumor paste-like substance which after having been applied should maintain its adhesive resistance.

The operation of the grinding machine is as follows:

When grinding profiled workpieces the sanding belt e runs around the roller b, the roller 0, and the profile roller d which is of such a shape as being practically the counterpart of the profiled workpiece. Adjacent to profile roller d, guide rollers t and t are-in operative engagement with the sanding belt e in such a way that the belt adapts itself to the profile of the workpiece and cannot slide off the profiled roller d. A workpiece w is placed upon table 1, which should correspondingly be adjusted, and pressed against the sanding belt being in contact with the profiled roller d. For reliable guiding action in the case of certain contour grinding stop bars f may be used. It is immaterial whether the workpiece is transported by hand or mechanically. When working intricate workpieces the profiled roller d can also be replaced by a stationary guide piece having the necessary contour.

When grinding veneered edges, profile roller d is replaced by contact roller d and belt e is then in operative engagement with this contact roller. Table 7 is then so adjusted that the contact roller d in operative engagement with the sanding belt, projects as far as the workpiece is to be groundolf. The workpiece is placed on the table and slid along the stop bar I.

In the case of slanting profiles or bevelled edges the sanding belt, by adjustment of motor g on the rotary flange a and the device for tighteningthe sanding belt, can be angularly adjusted. The profile and contact rollers, respectively, should then also be correspondingly adjusted. In some cases it should sufiice simply to adjust the table.

It is believed that the mode of constructing and using, and the many advantages of my invention, will be apparent from the foregoing detailed description thereof. It will further be apparent that while I have shown and described my invention in preferred form, many changes and modifications may be made in the structure disclosed, without departing from the spiritof theinvention, defined in the following claims.

I claim:

two rollers in the same plane so as to form a triangular unit, means for adjustably mounting the second roller for movement toward and away from the first roller to adjust the sanding belt, and an adjustable table disposed in front of said column and adapted to carry the workpieces, the endless belt being of such width that its edges project beyond the adjustable guiding means and are non-abrasive, and means for guiding each projecting edge of the sanding belt at the front, the back and the lateral side of the edge, and arranged at opposite sides of the area of contact of said adjustable guiding means with said belt, so that proper tracking of the sanding belt is ensured.

2. A profile and edge grinding machine as in claim 1, wherein the guiding means for the edges of the sanding belt consists of rollers engaging the front and back of the belt and means engaging the lateral side edges between the rollers.

3. A profile and edge grinding machine as in claim 1, wherein the means for guiding each edge of the sanding belt at three sides consists of guideways.

4. A profile and edge grinding machine as in claim 1, wherein the range of the projecting edges of the belt is rendered non-abrasive by strips of cloth glued onto the abrasive within said range.

5. A profile and edge grinding machine as in claim 1, wherein the range of the projecting edges of the belt is rendered non-abrasive by a smooth paste being applied onto the abrasive within said range.

1. In a profile and edge grinding machine having a I References Cited in the file of this patent UNITED STATES PATENTS 

